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nataraj

This is a distilled (and graphically enhanced) version of the one-step solution in a recent thread in the "other puzzles"
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Nataraj's gm-wing recipe:

· two strong links (in different candidates a,b), sharing one common cell
· a bi-value cell with those same candidates {a,b}, which sees either free end of the strong links.
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As an example, I'd like to take this Menneske M2534023 super hard (transposed):

Marty R. · Posted: Mon Nov 24, 2008 1:20 am Post subject:

OK, nice work and thanks for taking the time. But back to my fragment:

re'born · Joined: 28 Oct 2007 Posts: 80

nataraj · Posted: Mon Nov 24, 2008 9:01 pm Post subject:

Marty R. · Posted: Mon Nov 24, 2008 10:27 pm Post subject:

Nataraj,

Let's temporarily forget grips and barrels. We are connecting two remote pairs (not literally since one's a triple) XY and aXY. And I know the first part: those two cells are connected by two strong links on either X or Y.

Coincidentally or not, in both your example and my fragment, it's the triple that needed to be the common cell that shares both strong links.

So is it true that it's the aXY cell that must always be the common cell?

nataraj · Posted: Tue Nov 25, 2008 7:14 am Post subject:

Marty,

I guess we're getting closer to the essence of the matter.

First, we should decide whether to use "notation" or not. Initially I wrote this little guide here to get away from notation and present a more intuitive, graphical picture (there was someone over in the "others" forum said something like "I might be the only one here who doesn't understand notation, ..." lol)

One excellent example how notation for a gm-wing looks like, is Danny's explanation there in the other thread ("Another good Menneske"):

daj95376 · Joined: 23 Aug 2008 Posts: 3854

Marty: The typical M-Wing is four cells joined by strong links in two candidates -- the ones in the initial bivalue cell. Your fragment is just that! It only supports three cells of the necessary four. You lack a final strong link to join your third cell to a fourth cell Exclamation

The reason keith's general notation includes ...(X)... is because M-Wings with 6/8/... cells are also possible.
(Somewhere, I posted a 6-cell M-Wing.)

Marty R. · Posted: Tue Nov 25, 2008 5:59 pm Post subject:

Thank you both but I'm still not sure. Maybe it means that each of the four cells must be part of a strong link?

I didn't realize that this was as complicated as it looks to me. And as much as I appreciate the help, I think we're splitting hairs as to whether XY and aXY are remote or not (they're in different houses) and whether they're connected by two strong links or a strong and weak (to me a strong link is when there are two possibilities in a house).

Neither of you were around when I joined here and started pestering people with my questions. My spatial skills are zero and the only way I've been able to learn techniques is to somehow get a rule and then apply that rule to situations that I subsequently recognize. I'm strictly a mechanic and don't have an understanding of the underlying theory and have a hard time visualizing all this stuff.

Once again, I always appreciate the fact that people are willing to help.

nataraj · Posted: Tue Nov 25, 2008 7:30 pm Post subject:

Fair enough. The "generalized" part is indeed a very abstract / mathematical concept. Last thing I would want to do is get into splitting hairs ... Smile

(and I will learn to tell better stories Very Happy

)
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Marty R. · Posted: Tue Nov 25, 2008 10:16 pm Post subject:

nataraj · Posted: Wed Nov 26, 2008 2:01 pm Post subject:

I noticed the problems, too.

I'd only added the backup link in the "site help" forum, here goes:

Marty R. · Posted: Wed Nov 26, 2008 4:35 pm Post subject:

Yes, thanks, I used that second one yesterday when the first wouldn't connect.

daj95376 · Joined: 23 Aug 2008 Posts: 3854

[Withdrawn: An extraneous rehash of information already present.]

Marty R. · Posted: Sun Feb 07, 2010 10:54 pm Post subject:

Mogulmeister · Joined: 03 May 2007 Posts: 1151

Just to say to Nataraj that I am more graphically inclined and I like the spatial references! I like "flail" - it is not outdated, just more literary. Smile

nataraj · Posted: Fri Mar 12, 2010 7:17 pm Post subject:

keith · Posted: Sat Mar 13, 2010 8:10 am Post subject:

Another recipe is posted here:

http://www.dailysudoku.com/sudoku/forums/viewtopic.php?t=4366&start=21

Bud · Joined: 06 May 2010 Posts: 47 Location: Tampa, Florida

I am a new member and I think I understand Keith's M-Wing and I wanted to find out what a gM-wing is. However after looking at the example the only thing I can see is XY-Chain forcing or if you start at R6C7 an XY-Chain forcing wrap. This doesn't seem to be a pattern technique at all. Of course I have been wrong before.

Marty R. · Posted: Mon May 10, 2010 3:24 pm Post subject:

Hi Bud,

Welcome to the forum. I'd also like to find out what a gM-Wing is.
You can see Nataraj's definition at the start of this thread. You can see Keith's definition here:

http://www.dailysudoku.com/sudoku/forums/viewtopic.php?t=4366&highlight=humpty+dumpty&sid=5d128acf34316e16d11802c519e4a338

If you do find out, please let me know the answer. Wink

Bud · Joined: 06 May 2010 Posts: 47 Location: Tampa, Florida

Thanks Marty,
The example in the link looked like a pattern and I was able to follow Keith's logic. But the example here is completely different and still looks like an example of XY-Chain forcing.

Bud